#!/usr/bin/env bash

# Copyright 2018 The Cirq Developers
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#####
# The main file to use to setup your PYTHONPATH. It sets up all cirq modules on the path.
# The file can be sourced from any location with bash or zsh.
# Usage:
#   source dev_tools/pypath
#####


if [ -n "${ZSH_VERSION}" ]; then
    # shellcheck disable=2296,2298
    _PYPATH_BASE_DIR="${${(%):-%x}:a:h:h}"
else
    _PYPATH_BASE_DIR=$(d=$(dirname "${BASH_SOURCE[0]:?}") && cd "${d}/.." && pwd)
fi

if ! python --version | grep -q -F "Python 3."; then
    echo "python command does not start Python 3" >&2
    echo "Please use a virtual environment created for Python 3." >&2
    return 2
fi

_PYPATH_PREFIX="${_PYPATH_BASE_DIR}$(
    set -o pipefail
    cd "${_PYPATH_BASE_DIR}" &&
        env PYTHONPATH=. python dev_tools/modules.py list --mode folder |
        xargs printf ":${_PYPATH_BASE_DIR}/%s"
)" || return $?

[[ $PYTHONPATH == ${_PYPATH_PREFIX}* ]] ||
    export PYTHONPATH="${_PYPATH_PREFIX}${PYTHONPATH:+:}${PYTHONPATH}"

unset _PYPATH_BASE_DIR
unset _PYPATH_PREFIX
